1. Field of the Invention
The present invention relates to a finisher, and more particularly to a finisher which stacks sheets ejected from a copying machine or a printer and performs a process such as stapling and binding toward the stacked sheets.
2. Description of Related Art
Generally, an image forming apparatus such as an electrophotographic copying machine and a laser printer is provided with a finisher which sorts image-formed sheets and staples the sheets. A well-known type of this kind of finisher is one disclosed by Japanese Patent Publication No. 5-37315, wherein sheets are stacked and stapled on an inclined tray, and the lower part of the tray is opened to drop the stapled stack of sheets into a stack section under the tray. However, dropping the stapled stack of sheets into the stack section makes a noise, thereby affecting the office environment.
On the other hand, Japanese Patent Publication No. 4-66786 disclosed a sorter, wherein a stack bin is provided above a plurality of sort bins, and stacks of sheets are conveyed from the sort bins to the stack bin. This sorter does not make a noise when a stack of sheets is conveyed into the stack bin.
However, in this sorter, since sheet stack conveying means for conveying a stack of sheets into the stack bin is provided at a rear side of the sort bins, that is, the opposite side of the entrances of the sort bins, a space for the sheet stack conveying means itself and for its movement is necessary, thereby increasing the size of the apparatus.
Also, in the above-mentioned finisher, since the stack section is exclusively used for storing stapled stacks of sheets, a space for the stack section and a space for sheet stack take-out means are necessary, thereby increasing the size of the apparatus.